Linux环境下Swap配置方法

叁歲伎倆 2022-07-16 03:17 227阅读 0赞

http://blog.chinaunix.net/uid-26446098-id-4501237.html

场景:  
今天下午安装一个CentOS6.5操作系统，忘记配置swap分区。看看如何安装系统之后，增加和删除swap分区。  
方法如下：

1.内存占用情况

\[root@mysql01 Downloads\]\# free  
total used free shared buffers cached  
Mem: 1922020 1691448 230572 0 49844 1252236  
\-/+ buffers/cache: 389368 1532652  
Swap: 0 0 0

2.通过dd命令增加swap

\[root@mysql01 var\]\# dd if=/dev/zero of=/var/swap bs=1024 count=2048000  
2048000+0 records in  
2048000+0 records out  
2097152000 bytes (2.1 GB) copied, 5.9442 s, 353 MB/s

3.创建swap文件

\[root@mysql01 var\]\# mkswap /var/swap  
mkswap: /var/swap: warning: don't erase bootbits sectors  
on whole disk. Use -f to force.  
Setting up swapspace version 1, size = 2047996 KiB  
no label, UUID=daa18338-0371-4848-888d-49d662dafe3f

\[root@mysql01 var\]\# mkswap -f /var/swap  
Setting up swapspace version 1, size = 2047996 KiB  
no label, UUID=754e3fdf-258c-45f2-bb8e-4725862850d3

4.加载该文件：  
\[root@mysql01 var\]\# swapon /var/swap

5.看看swap是否生效  
\[root@mysql01 var\]\# free

6.查看swap当前状态：  
\[root@mysql01 var\]\# cat /proc/swaps  
Filename Type Size Used Priority  
/var/swap file 2047992 0 -1

7.添加至/etc/fstab

\[root@mysql01 var\]\# vim /etc/fstab

\#  
\# /etc/fstab  
\# Created by anaconda on Tue Sep 23 17:58:53 2014  
\#  
\# Accessible filesystems, by reference, are maintained under '/dev/disk'  
\# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info  
\#  
UUID=98f4128a-2ac6-4822-8624-300c4d818afc / ext4 defaults 1 1  
tmpfs /dev/shm tmpfs defaults 0 0  
devpts /dev/pts devpts gid=5,mode=620 0 0  
sysfs /sys sysfs defaults 0 0  
proc /proc proc defaults 0 0  
/var/swap swap swap defaults 0 0  
  
8.如果不再需要swap，可以清理该分区：  
\[root@mysql01 var\]\# swapoff /var/swap